What are some common methods for handling character encoding and charset conversion in PHP scripts?

Character encoding and charset conversion are important aspects of handling text data in PHP scripts to ensure proper display and processing of international characters. Common methods for handling character encoding and charset conversion in PHP include using the `mb_convert_encoding()` function, setting the `default_charset` directive in php.ini, and using the `header()` function to specify the charset in HTTP headers.

// Example of using mb_convert_encoding() function for charset conversion
$utf8_string = "Some UTF-8 encoded string";
$latin1_string = mb_convert_encoding($utf8_string, 'ISO-8859-1', 'UTF-8');
echo $latin1_string;
```

```php
// Example of setting default_charset directive in php.ini
ini_set('default_charset', 'UTF-8');
```

```php
// Example of specifying charset in HTTP headers using header() function
header('Content-Type: text/html; charset=UTF-8');